Sandblast gun



Nov. 8, 1949 G. J. PENN 2,487,355

SAND BLAST GUN Filed Oct. 13, l947 2 Sheets-Sheet l IIII l L /8 "l/ IIIIIMM, 50V v /Il 7 o l INVENToR. GLf/v/v J Pf/v/vo.

Arron/wx G. J. PENNO SAND BLAST GUN Nov. 8, 1949 2 Sheets-Sheet c Filed Oct. 13, 1947 ATTORNfY.

Patented Nov. 8, 1949l UNITED STATES PATENT OFFICE SANDBLAST GUN Glenn J. Penno, Longmont, Colo., animer to Tornado Manufacturing Company, Inc., Denver, Colo., a corporation oi' Colorado l Application October 13, 1347, Serial No. 773,433

lGlaim. 1

This invention relates to a gun for spraying iiuids or blasting with abrasives, and hasv for its principal object the provision of a simple and highly efiicient device which can be used for cleaning and preparing surfaces by means of an abrasive blast, and which will, when desired. prevent loss of the abrasive used in the blast.

Another object of the invention is to so construct the device that it may be quickly and easily converted into a spray gun for spraying surface coating compositions such as paints, enamels, etc.

A further object of the invention is to so construct the device that the portions which are subjected to rapid wear due to the abrasive action gj the material, can be quickly and easily removed and replaced without disassembling or interfering with the construction of the gunI per se, and in which the operative relation between the air stream and the solid or liquid material will be automatically adjusted when the device is changed over for different uses.

Other objects and advantages reside in the detail construction of the invention, which is designed for simplicity, economy, and efilciency. These will become more apparent from the following description.

In the following detailed description of the invention, reference is had to the accompanying drawing which forms a part hereof. Like numerals refer to like parts in all views of the drawing and throughout the description.

In the drawings:

Fig. 1 is a side view of the improved abrasive gun, illustrating it arranged for gathering and returning the used abrasive;

Fig. 2 is a front view thereof;

Fig. 3 is a detail view illustrating an air jet nozzle employed in the improved gun;

Figs. 4 and 5 are detail views of alternate forms of nozzle tubes which may be used with the improved gun;

Fig. 6 is a detail view of a nozzle tube retaining disc which is used in the gun;

Fig. '7 is a vertical, longitudinal section, taken on the line 11, Fig. 2; and

Fig. 8 is a fragmentary enlargement of the mid-portion of Fig. 7.

The abrasive gun comprises a solid metallic body portion I formed with a pistol-like hand grip II and provided with a hanging hook I2. A supporting boss I3 extends downwardly from the body portion I0, terminating in a threaded nipple I4. A nut I threaded on the nipple I4 acts to clamp a container cap I3 against the 2 boss I3. A container I1 is threaded into the cap I8 so as to be supported on the boss I3. v

The handle II is drilled with an air passage I3, the extremity of which is threaded to receive a hose nipple I3 to which an air supply hose 20 is connected. A cross air passage 2i is drilled into the butt of the body portion I0 and closed by means oi' a suitable plug 22. The cross passage 2I communicates between the air passage i8 and a valve chamber 23.

The valve chamber 23 is threaded to receive a valve housing 24 through which a valve stem 25 projects. The valve stem carries a valve member 26 against a head 21 formed on the stem 25. The stem is provided with a packing ring 28 which seals the stem. 25 to the housing 24.

The housing is provided with air ports 23, through which air passing beneath the valve 28 may discharge. When the housing 24 is in place in the valve chamber 23, the ports 23 align with an air discharge passage 30 extending through the muzzle of the body portion III.

The valve 26 is lifted from its seat by means of a trigger 3| hingedly mounted in a trigger cavity in the body portion I0 upon a trigger pin 32. .The trigger acts as a cam and bears against a head member 33 threaded on the lower extremity ci' the valve stem 25.

The discharge passage 30 is counter-bored for the major portion of its length to a larger diameter to provide a shoulder 35. I'he counterbored portion is designed to receive a plurality of interchangeable nozzle tubes. In Fig. 3 a nozzle tube 36 is illustrated which fits snugly into the counter-bored portion of the discharge pas- Y sage 30 and is locked in place therein by means of a U-shaped locking disc 31 which flts into an indented groove 33 in the nozzle tube 36.

'Ihe disc 31 is clamped against the forward extremity of the threaded nipple 39 by means of a clamping bushing 40 so that the nozzle tube is accurately located in a pre-determined position in the counter-bore of the air passage 30.

The inner extremity of the nozzle tube 3B carries a nozzle jet 4I which is illustrated more in detail in Fig. 3. The material to be sprayed enters the nozzle tube 36 through a feed port 42 formed in the lower wall thereof and opening to a feed passage 43.

The jet 4I is designed specifically for a certain fluid or material to be used in the gun. The nozzle tube 36 is similarly designed, and the size of the opening 42 and its position from the end of the tube are determined by the particular material or iluid with which it is to be used.

Thus, to change the gun for `different materials, it is only necessary to withdraw the nozzle tube and its jet and replace them with the proper nozzle tube and jet. Each jet is provided with a Venturi passage 44 for forming the air jet, and with a reduced extremity 45 which fits snugly into the end of the tube 38.

The material being projected by the gun is raised from the container l1 through a riser tube 46 which extends downwardly and forwardly to a point adjacent the bottom of the container. The suction created by the air stream owlng into the tube 38 draws the material upwardly in the riser tube I3 and feed passage 43.

For spraying liquids, such as cleaning solutions, etc., a nozzle tube such as illustrated in Fig. 4 is employed. For sand blasting and the like, a nozzle tube such as illustrated in Fig. 5 may be used, which is provided with a. protecting shield 41 threaded on the extremity of the tube for preventing sand and abrasive particles from being thrown back against the operators hand.

If the gun is used with abrasive material which it is desired to retain, a flexible hood 48 may be threaded onto the forward extremity of the nozzle tube 38. The hood has a flaring, funnel-like shape, and is preferably made of flexible material such as canvas, rubber, or the like, so that it may be pressed directly against the surface being blasted.

The sides of the hood 48 are provided with discharge screens 49 through which the air may escape. The hood is also provided with a receiving hopper 50 which is connected to a return tube 5i by means of a suitable union 52. The return tube 5i extends through, and is supported by, the container I1. The sand or other abrasive, after striking the surface to bev cleaned, falls into the hopper 50 and is drawn therefrom back to the container I1 by the vacuum in the latter, assisted by the pressure in the hood 48.

While a specific form of the improvement has tremity of said body portion in alignment with and communicating with said air passage, said bore being of larger diameter than said air passage; a feed passage opening through the bottom of said bore; means for supplying material to said feed passage; an air jet member positioned in the rearward extremity of said bore between said feed passage and said air passage; a nozzle tube positioned in the forward extremity of said bore andA iltted to said air jet at its rearward extremity, said nozzle tube having an opening in its bottom wall communicating with said feed passage; a peripheral receiving groove in said nozzle tube forwardly of said body portion; a U-shaped locking disc fitted into said groove; and means for clamping said disc to said body portion to lock said nozzle tube in place.

GLENN J. PENNO.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 537,160 King Apr. 9, 1895 847,269 Wise Mar. 12, 1907 2,133,149 Poncelet Oct. 11, 1938 2,230,690 Lanza Feb. 4, 1941 

